After analyzing the results, they found Christmastime was peak time for heart attacks in Sweden. In fact, they said the risk of cardiac arrest was 15 percent higher on Christmas Day and 37 percent higher on Christmas Eve, compared with the two weeks before and after the holiday.

“Understanding what factors, activities, and emotions precede these myocardial infarctions and how they differ from myocardial infractions experienced on other days,” the team wrote, “could help develop a strategy to manage and reduce the number of these events.”